Soil Analysis

Soil analysis is an essential part of developing a comprehensive fertilizer strategy for the coming season. This service involves gathering critical information on nutrient levels and other key soil traits.

At Summit, we offer a complete soil analysis service. Soil analysis is an essential part of developing a comprehensive fertilizer strategy for the coming season. It involves gathering critical information on nutrient levels and also other key soil traits such as organic carbon, electrical conductivity, pH and the soil’s phosphorus buffering index (PBI).

During a soil analysis, your local Summit Area Manager will take soil samples to get a deep understanding of your farm’s nutrient requirements. Drawing on local information and backed by our science, they will meet with you regularly to develop a long term fertilizer strategy designed to build the value of your farm.

Benefits of a Summit Soil Analysis

  • Independent laboratory testing
  • Rapid turnaround times
  • Wide range of nutrients measured
  • Practical recommendations based on results
  • Soil test reports available to view and download online via SummitConnect

Nutrients Analysed

Nutrient
Symbol
Units Used
Adequate Range Expected
Comments
Phosphorus
P
ppm (mg/kg)
15 - 45
Dependent on crop/pasture type and soil type.
Potassium
K
ppm (mg/kg)
40 - 120
Lupins and Canola are less sensitive to K deficiency. Clover and Medic require higher soil levels.
Sulphur
S
ppm (mg/kg)
5 - 15
Dependent on soil type.
Nitrate
NO3
ppm (mg/kg)
up to 30
Very mobile in the soil. May be lost to leaching.
Ammonium
NH4
ppm (mg/kg)
up to 20

Stable in the soil as it is a cation, but converts to Nitrate readily.

Copper
Cu
ppm (mg/kg)
>0.3
Soil tests for Copper are a guide only.
Zinc
Zn
ppm (mg/kg)
0.12-0.5
Dependent on soil pH. The more alkaline the soil (higher pH) the higher the soil Zinc level needs to be.
Organic Carbon
O.C.
%
1.0 - 3.0
Dependent on soil type and rainfall.
Electrical Conductivity
EC(salt)
dS/m
Levels <0.2 are="" generally="" considered="" negligible.="" levels="">0.8 can be said to be accumulating salt, and should be investigated further.</0.2>
pH
(CaCl2)
>5.0
Economic responses to applying lime to increase pH above 5.0 are doubtful. If subsoil pH is low, it may be necessary to increase topsoil pH >5.5 (CaCl2)
Aluminium
(CaCl2)
5.0

As pH declines (becomes more acidic) Aluminium levels can increase in some soil types. High Aluminium levels will affect root growth reducing their ability to explore large volumes of soil and therefore their access to nutrients and soil moisture. (Read the article on soil pH here)

PBI

PBI is a function of soil type. Generally as a soil contains more iron, clay and organic matter, the higher the PBI. (See article)

Nutrient
Symbol
Units Used
Nitrogen
N
%
Phosphorus
P
%
Potassium
K
%
Sulphur
S
%
Calcium
Ca
%
Magnesium
Mg
%
Copper
Cu
ppm
Zinc
Zn
ppm
Manganese
Mn
ppm
Boron
B
ppm
Sodium
Na
ppm
Iron
Fe
ppm
Nitrate
NO3
ppm
Chloride
Cl
%
Options
Molybdenum
Mo
ppm

Other nutrients can be analysed on request, including Cation Exchange Capacity (CEC) which involves analysing calcium, magnesium and sodium in conjunction with a potassium test to calculate CEC.